﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo05
{
    class Tx
    {
        public double Area(double a, double b) {
            return a * b;
        }

        public double Area(double r) {
            return 3.14 * r * r;
        }
    }
}
